Pretty cool!  Bob had much better results getting the engine to idle without a prop load than most builders using the EC2.  It just wasn't designed to work well that way.

Speaking of 20Bs,  I recently fixed my Bluemountain engine pod Manifold Pressure sensor and couldn't get the engine to run any more.  It would start but die almost immediately. After much head scratching, it turned out that the Bluemountain MP sensor had been leaking air which was causing the EC2/3 to see an artificially high manifold pressure.  I had unknowingly tuned it in this condition and when the leak was eliminated the EC3 saw a much lower MP so the engine ran too lean to run.   I had to increase the injector flow rate (Mode 3) from 120 to 158.   This was a bit tricky because the engine has to be running to adjust the flow rate.   Set max rich mixture and/or turn on cold start in mode 0 to get it running then quickly go to mode 3 to increase flow rate.

So, the message to 20B users is to be aware that the default EC2/3 injector flow rate is probably set much to low to run properly.  I had set it based on my initial tuning with the leaky BM pressure sensor..

Tracy